Device for retrieving a unit from a storage system

Abstract

To provide a storage system, and a stacked load handling device for lifting and moving stacked containers in the storage system.SOLUTION: A storage system comprises a plurality of rails or tracks arranged with a lattice pattern above stacks of containers. The lattice pattern comprises a plurality of lattice spaces, and each of the stacks is positioned in an installation area of a single lattice space. A stacked load handling device 100 moves in a lateral direction on the rail or the track above the stacks. The stacked load handling device comprises a container reception space positioned above the rail or the track during use thereof, and a lifting device provided so as to lift containers from the stacks to the container reception space. The stacked load handling device has an installation area that occupies only the single lattice space in the storage system during use thereof.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to an apparatus for retrieving units from a storage system. Specifically, although not exclusively, the present invention relates to a robotic device for handling storage containers or storage boxes in a storage vault comprising a grid of stacked units.

Background Art

[0002] Some commercial and industrial activities require systems that enable the storage and retrieval of a number of different products. One known system for the storage and retrieval of items in multiple product lines involves placing storage boxes or storage containers in rows of shelves arranged in aisles. Each box or container holds multiple products of one product type. The aisles provide access between the rows of shelves so that the required products can be retrieved by a worker or a robot traversing the aisle. However, it will be appreciated that the need to provide aisle space to access the products means that the storage density of such systems is relatively low. In other words, the size of the space actually used for storing the products is relatively small compared to the size of the space required for the storage system as a whole.

[0003] Another approach that provides a significant improvement in storage density is where the containers are stacked on top of each other and the stacks are arranged in rows. The containers are accessed from above, eliminating the need for aisles between the rows and allowing more containers to be stored in a given space.

[0004] Methods for handling containers stacked in columns have been well known for decades. In some such systems, for example as described in U.S. Patent No. 2,701,065, unsupported stacks of containers are arranged in columns to reduce the storage volume associated with storing such containers while providing access to specific containers if needed. Access to a given container is made possible by providing a relatively complex elevator mechanism that can be used to stack containers and to remove a given container from the stack. However, the cost of such systems is unrealistic in many situations and they have been mainly commercialized for the storage and handling of large shipping containers.

[0005] The concept of using unsupported stacks of containers and providing a mechanism for retrieving and storing specific containers has been further developed, for example as described in EP0767113B (Cimcorp). Cimcorp discloses a mechanism for removing a plurality of stacked containers using a robotic payload handler in the form of a rectangular tube that is configured to be lowered in height around the stack of containers and to grip a container at any height in the stack. In this method, several containers can be lifted out of the stack at once. The movable tube can be used to move several containers from the top of one stack to the top of another stack, or to move containers from the stack to an external location or from an external location to the stack. Such a system can be particularly useful when all the containers in a single stack contain the same product (understood as a single product stack). The payload handler can be used, for example, to add a plurality of containers containing a single type of product to a storage facility and to obtain one or more containers from two or more single product stacks to create a multi-product shipping stack, and to move containers between single product stacks. This example is obtaining wooden boxes of vegetables in a central warehouse to create a multi-product order for delivery to a retail store.

[0006] In the system described by Cimcorp, the height of the tube body must be at least as high as the height of the tallest stack of containers so that the tallest stack of containers can be retrieved in a single operation. Thus, when used in an enclosed space such as a warehouse, the maximum height of the stack is restricted by the need to accommodate the tube body of the load handler. Furthermore, the system is not well-suited for the selection of a single container from a stack of multiple products.

[0007] Online retail businesses that sell multiple product categories, such as online grocery stores and supermarkets, require a system that can store hundreds of thousands of different product categories. The use of single-product stacks in such cases is not practical because a very large floor area would be required to accommodate all of the necessary stacks. Furthermore, some items, such as fragile or low-order-frequency items, may preferably be stored in small quantities, making single-product stacks an inefficient solution.

[0008] Therefore, for some applications, the use of multiple-product stacks in which the containers making up each stack can hold different products is preferred to maximize the storage density of the system. The stored items must remain reasonably quickly and easily accessible so that the multiple different items required to fulfill a customer order can be retrieved from the storage system in an efficient manner, even if some of the required items are stored under some of the other containers at a lower height within the stack.

[0009] International patent application WO98 / 049075A (Autostore), the content of which is incorporated herein by reference, describes a system in which multiple-product stacks of containers are arranged inside a frame structure. This type of system is schematically shown in Figures 1 to 4 of the accompanying drawings.

[0010] As shown in FIGS. 1 and 2, stackable containers, understood as boxes 10, are stacked on top of each other to form a stack 12. The stack 12 is disposed in a grid frame structure 14 in a warehouse environment or a manufacturing environment. FIG. 1 is a schematic perspective view of the frame structure 14, and FIG. 2 is a view looking down from above at the stack 12 of boxes 10 disposed within the frame structure 14. Each box 10 typically holds a plurality of product items (not shown), and the articles of the products within the box 10 may be the same or may be of different product types depending on the application.

[0011] The frame structure 14 includes a plurality of upright members 16 that support horizontal members 18, 20. A first set of parallel horizontal members 18 is disposed perpendicular to a second set of parallel horizontal members 20 to form a plurality of horizontal grid structures supported by the upright members 16. The members 16, 18, 20 are typically fabricated from metal. The boxes 10 are stacked between the members 16, 18, 20 of the frame structure 14 such that the frame structure 14 protects the stack 12 of boxes 10 from horizontal movement and guides the vertical movement of the boxes 10.

[0012] The top height of the frame structure 14 includes rails 22 disposed in a grid pattern across the top of the stack 12. With additional reference to FIGS. 3 and 4, the rails 22 support a plurality of robotic payload handling devices 30. A first set 22a of parallel rails 22 guides the movement of the payload handling devices 30 in a first direction (X) across the top of the frame structure 14, and a second set 22b of parallel rails 22 disposed perpendicular to the first set 22a guides the movement of the payload handling devices 30 in a second direction (Y) perpendicular to the first direction. In this way, the rails 22 enable the lateral two-dimensional movement of the payload handling devices 30 in a horizontal X-Y plane such that the payload handling devices 30 can be moved to any position above the stack 12.

[0013] The load handling device 30 is further described in Norwegian Patent No. 317366, the content of which is incorporated herein by reference. FIGS. 3(a) and 3(b) are schematic perspective views of the load handling device 30 from the rear and front, respectively, and FIG. 3(c) is a schematic front perspective view of the load handling device 30 lifting the box 10.

[0014] Each load handling device 30 includes a vehicle 32 that is disposed above the stack 12 and is arranged to travel in the X and Y directions on the rails 22 of the frame structure 14. The first set of wheels 34 consists of a pair of wheels 34 on the front side of the vehicle 32 and a pair of wheels 34 on the rear side of the vehicle 32, and is arranged to engage with two adjacent rails of the first set 22a of the rails 22. Similarly, the second set of wheels 36 consists of a pair of wheels 36 on each side of the vehicle 32 and is arranged to engage with two adjacent rails of the second set 22b of the rails 22. Each set of wheels 34, 36 can be lifted and lowered such that either the first set of wheels 34 or the second set of wheels 36 engages with the respective set of rails 22a, 22b at any given time.

[0015] When the first set of wheels 34 is engaged with the first set 22a of the rails and the second set of wheels 36 is lifted away from the rails 22, the wheels 34 can be driven using a drive mechanism (not shown) housed in the vehicle 32 to move the load handling device 30 in the X direction. To move the load handling device 30 in the Y direction, the first set of wheels 34 is lifted away from the rails 22 and the second set of wheels 36 is lowered into engagement with the second set 22b of the rails. Then, the drive mechanism can be used to drive the second set of wheels 36 to effect movement in the Y direction.

[0016] The load handling device 30 is equipped with a crane device 40. The crane device 40 includes a cantilever arm 42 that extends horizontally from the topmost part of the vehicle 32. A gripping plate 44 is suspended from the cantilever arm 42 by four cables 46. The cables 46 are connected to a winding mechanism (not shown) housed within the vehicle 32. The cables 46 may be wound in or out from the cantilever arm 42 so that the position of the gripping plate 44 relative to the vehicle 32 can be adjusted in the Z direction.

[0017] The gripping plate 44 is adapted to engage with the topmost part of the box 10. For example, the gripping plate 44 may include a pin (not shown) that engages with corresponding holes (not shown) at the edges forming the top surface of the box 10, and a sliding clip (not shown) that can engage with the edges for gripping the box 10. The clip is driven to engage with the box 10 by a suitable drive mechanism housed within the gripping plate 44, and the drive mechanism is powered and controlled by a signal sent through the cable 46 itself or through a separate control cable (not shown).

[0018] To remove the box 10 from the top of the stack 12, the load handling device 30 is moved as required in the X and Y directions such that the gripping plate 44 is positioned above the stack 12. Next, the gripping plate 44 is lowered vertically in the Z direction to engage with the box 10 at the top of the stack 12 as shown in FIG. 3(c). The gripping plate 44 grips the box 10 and is then pulled upward by the cable 46 with the box 10 attached. At the uppermost position of its vertical travel, the box 10 is received under the cantilever arm 42 and held above the height of the rail 22. In this way, the load handling device 30 is moved to different positions in the X-Y plane and the box 10 can be carried with the load handling device 30 to transport the box 10 to another location. The cable 46 is of a length such that the load handling device 30 can retrieve and place the box from any height of the stack 12 including floor level. The vehicle 32 is heavy enough to balance the weight of the box 10 and remain stable during the lifting process. The weight of the vehicle 32 may be partly constituted by a battery used to power the drive mechanism for the wheels 34, 36.

[0019] As shown in FIG. 4, a plurality of identical load handling devices 30 are provided such that each load handling device 30 can be operated simultaneously to enhance the processing capacity of the system. The system shown in FIG. 4 includes two specific locations understood as ports 24 through which the box 10 can be transferred into and out of the system. An additional conveyor system (not shown) is associated with each port 24 such that the box 10 transported to the port 24 by the load handling device 30 can be transferred by the conveyor system to another location such as, for example, a collection station (not shown). Similarly, the box 10 may be moved from an external location such as, for example, a box filling station (not shown) to the port 24 by the conveyor system to replenish the inventory in the system and then transported to the stack 12 by the load handling device 30.

[0020] Each load handling device 30 can lift and move one box 10 at a time. If it is necessary to retrieve a box 10 that is not located at the top of the stack 12 (the "target box"), the box 10 on top (the "non-target box") must first be moved to enable access to the target box 10.

[0021] Each of the load handling devices 30 is under the control of a central computer. Each individual box 10 in the system is tracked so that the appropriate box 10 can be retrieved, transported, and exchanged as needed.

[0022] The system described with reference to FIGS. 1-4 has many advantages and is suitable for a wide range of storage and retrieval operations. Specifically, this system allows for very dense storage of products and provides a very economical way to store a very wide variety of different items in boxes 10, while allowing for reasonably economical access to all boxes 10 when acquisition is required.

[0023] For high-capacity systems where the speed of operation is important, it is important to maximize the performance of each load handling device in terms of operating speed, battery life, reliability, lifting capacity, stability, etc. Therefore, it is considered desirable to provide a load handling device that offers improved performance in one or more of these areas.

[0024] Also, in order to enable an increase in the speed at which items can be retrieved from the storage system, it may be desirable to increase the number of load handling devices used at any given time. For example, the applicant's co-pending international patent application PCT / GB2013 / 051215, the content of which is incorporated herein by reference, describes a storage system in which a plurality of each of two different types of load handling devices are provided. One type of load handling device is adapted to lift a plurality of boxes from a stack in a single operation and to enable the target box in the stack to be accessed by a second type of single-box load handling device. In such cases, it may be desirable to reduce the size of the load handling devices in order to minimize the situation where the optimal movement path for one device is obstructed by the presence of the other device.

[0025] The present invention has been devised against this background.

Prior Art Documents

Patent Documents

[0026]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Summary of the Invention

[0027] In one aspect, the present invention relates to a load handling device for use in a storage system comprising a lattice frame for accommodating a plurality of stacks of containers. The load handling device is disposed above a stack of containers, can lift the containers from the stack, and can move the containers laterally to another location. Advantageously, each load handling device substantially occupies only a single lattice space in the storage system.

[0028] Accordingly, the present invention provides a load handling device for lifting and moving stacked containers in a storage system comprising a plurality of rails or tracks arranged in a lattice pattern above the stack of containers, wherein the lattice pattern comprises a plurality of lattice spaces, each stack being positioned within the footprint of substantially only a single lattice space, the load handling device being configured to move laterally above the stack on the rails or tracks, the load handling device comprising a container receiving space positioned above the rails or tracks during use and a lifting device arranged to lift the containers from the stack into the container receiving space, wherein the load handling device has a footprint that substantially occupies only a single lattice space in the storage system during use.

[0029] The load handling device according to an embodiment of the present invention includes a container receiving space in which a container can be lifted. The container receiving space is disposed below a vehicle module in which components such as power components, control components, drive components, and lifting components are housed.

[0030] In a preferred embodiment of the present invention, the load handling device has an outer housing that substantially surrounds the container receiving space. The outer housing preferably has a cubic shape.

[0031] By arranging the bulky components of the load handling device above the container receiving space, the installation area of the load handling device is reduced as compared to the cantilever design shown in FIGS. 3(a) to 3(c) described in Norwegian Patent No. 317366, where the bulky components are accommodated in a vehicle module arranged on one side of the container receiving space. Advantageously, the load handling device of the present invention occupies the space above only one stack of containers in the frame, in contrast to the cantilever design shown in FIGS. 3(a) to 3(c) that occupies the space above two stacks. Thanks to the present invention, this reduced installation area makes it possible to accommodate more load handling devices and means that the operating efficiency of the storage system can be improved because the possibility that one load handling device obstructs the optimal path of another load handling device is reduced.

[0032] The load handling device preferably comprises a set of wheels for supporting the load handling device above the stack. For example, the lateral movement of the load handling device may be guided by rails arranged above the frame. The rails are arranged in a grid pattern to enable two-dimensional movement of the load handling device in the horizontal plane. The wheels can engage with the rails. Two sets of wheels may be provided, with one set arranged to engage with a first set of rails to guide the movement of the load handling device in a first direction and the other set arranged to engage with a second set of rails to guide the movement of the load handling device in a second direction.

[0033] In an embodiment of the present invention, the wheels are arranged around the container receiving space. The wheels may be driven by one or more motors housed in the vehicle module. The drive may be transmitted from the motor of the vehicle module to the wheels by drive transmission means arranged around the container receiving space. For example, the drive transmission means may comprise a suitable configuration of a pulley and a drive belt.

[0034] Alternatively, the wheels may comprise built-in motors, such as motors built into the wheel hubs for example. In this way, each wheel is a self-contained drive unit and no drive belt is required. This configuration is advantageous for reducing the size of the load handling device and facilitating after-sales service.

[0035] One or both sets of wheels may be configured to be raised and lowered relative to the other set of wheels. One or more wheel lifting motors or other wheel lifting devices may be housed in the vehicle module for this purpose.

[0036] The vehicle module can house a hoisting machine or a crane device for lifting the container into the container receiving space. The crane device can comprise one or more motors for lifting the container, and that motor or each motor of the crane device can be housed in the vehicle module.

[0037] The crane device may comprise a gripping device configured to grip the container from above. The gripping device may be suspended from a cable that can extend out from and retract into the vehicle to move the gripping device in the vertical direction.

[0038] In another embodiment, the load handling device is provided with a lifting device arranged to lift a single container from a stack into the container receiving space. The lifting device may comprise a pair of lifting arms arranged on either side of the container receiving space, in which case the lifting device may comprise a gripping device mounted between the ends of the arms and arranged to grip the container from above.

[0039] The load handling device preferably has a center of mass positioned substantially directly above the gripping device when the gripping device is lowered below the container receiving space.

[0040] In another embodiment, the lifting device comprises a rod or cable arranged to engage a vertical path formed in the side wall of the container. The path may be accessed by an opening in the top surface of each container. In such a configuration, no vertical space is required in the storage system.

[0041] The rod or cable may carry a fixing mechanism arranged to releasably engage the container. For example, the fixing mechanism may comprise one or more laterally extensible arms for engaging the surface of the container. The fixing mechanism may be operated remotely, for example, by a wire extending through a tubular bore of the rod or cable.

[0042] A load handling device according to another embodiment of the present invention comprises an upper part, a lower part including a container receiving space, and lifting means for lifting a container into the container receiving space. The lifting means preferably comprises a lifting motor housed in the upper part above the container receiving space. The lower part preferably comprises a wheel assembly to facilitate lateral movement of the load handling device relative to the frame, and the upper part also comprises at least one motor for driving one or more wheels of the wheel assembly.

[0043] The lower part may comprise a frame structure for supporting the wheels of the wheel assembly. The frame structure may be arranged around the container receiving space. For example, the container receiving space may be bounded on four sides by the frame structure. One or more elements of the frame structure may move the first set of wheels up and down relative to a second set of wheels, thereby facilitating engagement of either the first set of wheels or the second set of wheels with respective rails or tracks of the first or second set. The movable element of the frame structure may be driven by a motor housed in the upper part of the load handling device.

[0044] The load handling device of the present invention is preferably a self-propelled robotic vehicle.

[0045] In another aspect, the present invention resides in a storage system comprising a frame for accommodating a plurality of stacks of containers and one or more of the foregoing load handling devices. Each load handling device substantially occupies a single grid space corresponding to the area occupied by only one stack of containers.

[0046] Accordingly, the present invention provides a storage system comprising a first set of parallel rails or tracks, and a second set of parallel rails or tracks extending across the first set in a substantially horizontal plane to form a grid pattern comprising a plurality of grid spaces, a plurality of stacks of containers positioned below the rails and arranged such that each substantially occupies the footprint of a single grid space, a load handling device as described above arranged to move laterally above the rails and above the stacks, and a lift device arranged to position the load handling device above a container receiving space above the rails and to lift a single container from a stack into the container receiving space, wherein the load handling device has a footprint that substantially occupies only a single grid space in the storage system.

[0047] In another aspect, the present invention provides a storage system comprising a frame for accommodating a plurality of stacks of a plurality of containers, a first handling device capable of lifting a plurality of containers from a stack in a single operation, and a second handling device capable of lifting a single container and moving it laterally. The first and second handling devices are disposed above the frame and are independently movable to access different stacks. The second handling device is of the type described above and occupies a space substantially corresponding to only one stack of a plurality of containers.

[0048] In this aspect, the provision of a first handling device capable of lifting a plurality of containers from a stack in a single operation, together with a second handling device capable of lifting a single container and moving the container laterally, provides an optimal solution when attempting to retrieve a container located in the middle or at the bottom of a stack. In such cases, only two lifting operations need to be performed to retrieve the target container, which greatly improves the speed and efficiency of the retrieval process compared to prior art configurations where only one container can be lifted at a time.

[0049] The storage system may further comprise one or more port locations from which a container can be removed and / or to which a container can be added to the storage system. The load handling device of the present invention may be capable of transporting a target container from a stack to a port location. The container may comprise a box without a top surface. The containers may be arranged to be connected or engaged with each other in the vertical direction when formed in a stack.

[0050] In a typical application, a plurality of handling devices may be used such that a plurality of containers can be lifted and moved simultaneously. The handling devices may be of different types and may be selected to balance the cost and energy consumption of the system with the speed and flexibility of operation. One advantage of the present invention is that since the load handling device occupies only the space above a single stack, the efficiency of a system of multiple devices can be improved compared to prior art load handling device designs that occupy two or more stack spaces. The gain in efficiency can result from being able to fit more load handling devices in a given system, from optimizing the routing of the devices using the space obtained from the reduced device footprint, or from a combination of these factors.

[0051] The preferred and / or optional features of each aspect of the present invention may be used alone or in suitable combinations with other aspects of the present invention.

[0052] Here, embodiments of the present invention will be described by way of example only, with reference to the remaining attached drawings in which like reference numerals are used for like features.

Brief Description of the Drawings

[0053]

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Figure 17

DETAILED DESCRIPTION OF THE INVENTION

[0054] FIG. 5 shows a load handling device 100 according to an embodiment of the present invention. The load handling device 100 includes a vehicle 102 equipped with a hoisting or crane mechanism 104 for lifting a storage container or box 106, also known as a tote box, from above. The crane mechanism 104 includes a hoisting cable 108 and a gripping plate 110. The gripping plate 110 is configured to grip the top surface of the container 106 in order to lift the container 106 from a stack of containers 106 in a storage system of the type shown in FIGS. 1 and 2.

[0055] Referring also to FIGS. 6(a) and 6(b), the vehicle 102 includes an upper portion 112 and a lower portion 114.

[0056] The lower part 114 is attached with two sets of wheels 116, 118 that run on rails provided at the uppermost part of the frame of the storage system. At least one wheel of each of the sets 116, 118 is driven to enable the movement of the vehicle 102 in the X and Y directions respectively along the rails. As will be described later, one or both sets of the wheels 116, 118 can move vertically to lift each set of wheels away from their respective rails, thereby enabling the vehicle 102 to be moved in a desired direction.

[0057] The wheels 116, 118 are arranged in the lower part 114 around a cavity or recess 120 known as a container receiving recess. The recess 120 is sized to receive the box 106 when the box 106 is lifted by the crane mechanism 104 as shown in FIG. 6(a). When in the recess 120, the box 106 is lifted away from the lower rails so that the vehicle 102 can move laterally to different locations. For example, when reaching a target location such as another stack, an access point in the storage system, or a conveyor belt, the box 106 can be lowered from the recess 120 (as shown in FIG. 6(b)) and released from the gripping plate 110.

[0058] The upper part 112 of the vehicle 102 houses all the major bulky components of the load handling device as shown in FIG. 6(c). The upper part 112 houses the battery and associated electronic devices, the control device and communication devices, the motors for driving the wheels 116, 118, the motor for driving the crane mechanism 104, and other sensors and systems.

[0059] In this method, the installation area of the vehicle 102 is larger than the dimensions of the box 106 by just enough to accommodate the wheels 116, 118 on either side of the recess 120. In other words, the vehicle 102 occupies a single grid space in the storage system. Therefore, in this method, the vehicle 102 takes up the minimum possible size of space in the X-Y plane and has an installation area that is approximately half of the installation area of the prior art cantilever design shown in FIG. 3. For comparison, FIG. 7 shows the load handling device 100 according to the present invention in use in a storage system of the type shown in FIGS. 1 and 2, together with a prior art cantilever type load handling device 30 of the type shown in FIG. 3. It can be seen that the prior art device 30 occupies twice the stacking space compared to the device 100 of the present invention, which has a lower height but a smaller installation area.

[0060] In the present invention, since the load of the container is suspended between a pair of wheels on each side of the vehicle, the load handling device 100 of the present invention can provide improved stability, improved load handling capacity, and reduced weight compared to the cantilever type prior art load handling device 30. In contrast, the prior art device 30 must have a relatively heavy vehicle module in order to balance the load in a cantilever configuration.

[0061] FIGS. 8 to 12 show an embodiment of the present invention. The upper part 112 of the vehicle 102 houses three main motors, namely, a Z-axis drive motor 150 used to raise and lower a hoisting cable 108 wound around a spool 109 mounted on a drive shaft installed on the opposite side of the vehicle 102, an X-axis drive motor 152 that drives the first set of wheels 116, and a Y-axis drive motor 154 that drives the second set of wheels 118. The upper part 112 of the vehicle also houses a battery 156 for supplying power to the motors, a control device, sensors, and other components, as described previously with reference to FIG. 6(c).

[0062] The drive is transmitted from the X-axis drive motor 152 and the Y-axis drive motor 154 to their respective sets of wheels 116, 118 using a belt drive mechanism. The X-axis drive motor 152 drives a pulley 160 that is connected to a short drive shaft 162 extending across the vehicle body. The drive is transmitted by an X-axis drive belt 164 from the short drive shaft 162 to each wheel in the first set of wheels 116. The Y-axis drive motor 154 drives a pulley 170 that is connected to a long drive shaft 172 extending across the vehicle body in a direction perpendicular to the short drive shaft 162. The drive is transmitted by a Y-axis drive belt 174 from the long drive shaft 172 to each wheel in the second set of wheels 118.

[0063] The belt-driven wheels 116, 118 are mounted on the bottom of the lower portion 114 of the vehicle 102. By using drive belts 164, 174 to transmit the drive from the motors to the wheels, the motors 152, 154 can be mounted on the upper portion 112 of the vehicle.

[0064] In this embodiment, as most clearly shown in FIGS. 9, 11, and 12, the first set of wheels 116 can be raised away from the rails or lowered towards the rails using a wheel positioning mechanism. Each wheel 116 is mounted on an arm 180 that is pivotally mounted at its outer end. The inner end of each arm 180 is connected to the lower end of a respective link mechanism 182. The upper ends of both link mechanisms 182 are connected to the lower end of a common link mechanism 184. Further, the upper end of the common link mechanism 184 is connected to a lever arm 186 that is moved by a motor 188. By operating the motor 188 to pull the common link mechanism 184 upward, the first set of wheels 116 can be raised so that only the second set of wheels 118 engages the rails, enabling movement of the vehicle 102 in the Y direction. By operating the motor 188 to push the common link mechanism 184 downward, the first set of wheels 116 moves downward to engage the rails and lift the vehicle so that the second set of wheels 118 is lifted away from the rails as shown in FIGS. 9, 11, and 12. Thus, the vehicle 102 can move in the X direction.

[0065] The second set of wheels 118 is mounted on fixed T-shaped pieces 190 that are disposed at both ends of the lower portion 114 of the vehicle 102.

[0066] FIGS. 8, 9, and 12 show the load handling device 100 with the box 106 lifted into the recess 120. FIG. 11 shows the load handling device 100 with the box 106 beneath the device 100 and the gripping plate 110 attempting to engage the box 106. The wheels 116, 118 and associated support pieces, and the link mechanisms and drive belts 164, 174 are disposed around the edge of the recess 120 so that the upper portion 112 of the vehicle 102 is firmly supported.

[0067] FIG. 13 shows a wheel 200 suitable for use as one of the wheels 116, 118 of the load handling device 100. The wheel 200 has a toothed central path 202 that forms a pulley for cooperating with the drive belts 164, 174. The path 202 is bounded by two rubber tires 204 that press against the rail during use. The wheel 200 may be mounted on the arm 180 using an axle (not shown) that extends through the axle hole 206 of the wheel 200. This wheel design is compact and balanced to minimize wear, and the tires 204 keep the drive belts 164, 174 in a straight line during use.

[0068] FIG. 14 shows two wheels 200 mounted on the frame structure 210 of a load handling device according to another embodiment of the present invention. As in the previous embodiment, in this embodiment, the load handling device includes an upper portion 112 that houses the main components of the device, and a lower portion that has a recess 120 for housing a box, with the wheels 200 arranged on four sides of the recess (only the wheels on one side are shown in FIG. 14).

[0069] In this case, the frame structure 210 includes two parallel panels that house the wheels 200 therebetween. The drive belt 212 is provided to transmit drive from a motor housed in the upper portion 112 of the vehicle to the wheels 200.

[0070] Referring additionally to FIGS. 15 and 16, the wheels 200 in this embodiment can be raised and lowered by moving the frame structure 210 relative to the upper portion 112 of the vehicle. The frame structure 210 is mounted on the main body 230 of the upper portion 112 of the vehicle using rails 232. The rails 232 are fixed to the main body 230 in a vertical orientation, and the frame structure 210 is slidably mounted on the rails 232.

[0071] The frame structure 210 is held by a pair of link mechanisms 240 extending between the panels. The bottom ends of the link mechanisms 240 are attached to respective shafts 242 spanning the gap between the panels. The upper ends of the link mechanisms 240 are rotatably attached to threaded bosses 246 mounted on a threaded horizontal drive shaft 244. The bosses 246 are slidably attached to a horizontal rail 248.

[0072] The drive shaft 244 is driven by a motor 250 using a drive belt (not shown). When the drive shaft 244 is rotated in a first direction, the upper ends of the link mechanisms 240 move away from each other to push the frame structure 210 downward, thereby lowering the wheels 200 onto the rail. When the drive shaft 244 is rotated in a second opposite direction, the upper ends of the link mechanisms 240 move together to pull the frame structure 210 upward and lift the wheels 200.

[0073] Only one frame structure 210 with two wheels 200 is shown in FIGS. 14 - 16, but it is understood that the same frame structure 210 is provided on the opposite side of the vehicle. Both frame structures 210 are raised and lowered by a common motor, and thus, this first set of wheels 200 can be lifted and lowered in harmony to control the engagement of the four wheels 200 with the rail extending in a first direction across the frame. Although not shown in FIGS. 14 - 16, the vehicle includes another set of wheels arranged to engage a rail extending in a second perpendicular direction across the frame when the first set of wheels is lifted.

[0074] It is understood that many different variations and improvements are possible. For example, both sets of wheels may be powered by a single motor in a suitable transmission configuration to direct the power to the appropriate set of wheels. In other embodiments, one or more of the wheels may include a built - in motor, or a motor positioned adjacent to the wheel. This example is shown in FIG. 17.

[0075] Referring to FIG. 17, this shows a load handling device 252 according to a further embodiment of the present invention. The device 252 has a cuboid-shaped outer housing 254 with a plurality of wheels 256 mounted near the lower edge 258 of the housing 254. The wheels 256 are wheels with hubs to which motors are attached, with each wheel 256 having a motor built into the hub 260 of the wheel 256. The motors are used to directly drive the respective wheels 256, so this embodiment does not require a drive belt connecting the wheels and the drive motors.

[0076] In this example, the motors are powered by batteries located within the side walls 262 of the lower part 264 of the housing 254, adjacent to the container receiving space 266 of the device 252. Positioning the batteries low down in this way has the beneficial effect of lowering the center of gravity of the device 252, thereby improving the stability of the device 252 and allowing for greater acceleration and deceleration. The device 252 is otherwise the same as the previous embodiments and houses a similar mechanism for raising and lowering the wheels 256 and a similar lifting device for lifting the container into the container receiving space 266. The batteries located in the side walls 262 are also used to power these components.

[0077] In any of the previously described embodiments, the mechanism used to lift the container into the container receiving space can take any suitable form. For maximum stability and load capacity, it is desirable to provide four lifting cables with one cable arranged near each corner of the device, although different configurations may be used if necessary, for example with fewer cables. Conveniently, all the cables are wound in and out using a single motor, although two or more motors may be used if necessary.

[0078] Instead of a motor, the mechanism used to lift the wheel may use a linear actuator such as a linear motor or a hydraulic ram. Other means of powering the load handling device, such as using overhead power transmission or supplying power through the rails on which the device runs instead of using battery power, will be apparent to those skilled in the art.

[0079] It is understood that the features described in connection with a particular embodiment may be replaceable with the features described in connection with other embodiments. For example, the wheel with the hub to which the motor is attached and described in connection with FIG. 17 may be used in any of the other embodiments, and / or the battery may be positioned lower down adjacent to the container receiving space in any of the embodiments in order to improve stability and to enhance acceleration / deceleration. Other changes and improvements not explicitly described above will also be apparent to the skilled reader. The invention described in the original claims of the present application is appended below. [1] In a storage system comprising a plurality of rails or tracks arranged in a grid pattern above a stack of containers, a cargo handling device for lifting and moving the stacked plurality of said containers, wherein the grid pattern comprises a plurality of grid spaces, each stack is positioned within an installation area of only a single grid space, the cargo handling device is configured to move laterally above the stack and on the rails or tracks, the cargo handling device comprises a container receiving space positioned above the rails or tracks during use, and a lifting device arranged to lift a container from the stack into the container receiving space, in a cargo handling device. The cargo handling device is characterized in that, during use, it has an installation area that substantially occupies only a single grid space in the storage system. [2] The cargo handling device according to [1], comprising an upper part for accommodating components such as power components, control components, drive components, and / or lifting components, and a lower part including the container receiving space, wherein the lower part is arranged directly below the upper part. [3] The cargo handling device according to [1] or [2], further comprising an outer housing that substantially surrounds the container receiving space. [4] The cargo handling device according to [3], wherein the outer housing is substantially formed in a cubic shape. [5] The cargo handling device according to any one of [1] to [4], wherein the cargo handling device is configured to move in a first direction along a first set of rails or tracks and in a second direction along a second set of rails or tracks, wherein the second direction intersects the first direction. [6] The load handling device according to any one of [1] to [5], comprising a wheel assembly having a first set of wheels for engaging with the first set of rails or tracks to guide the movement of the device in a first direction, and a second set of wheels for engaging with the second set of rails or tracks to guide the movement of the device in a second direction. [7] The load handling device according to [6], wherein the wheels are arranged around the periphery of the container receiving space. [8] The load handling device according to [6] or [7], further comprising a frame structure for supporting the wheels of the wheel assembly. [9] The load handling device according to [8], wherein the frame structure is part of an outer housing of the load handling device.

[10] The load handling device according to [8] or [9], wherein the frame structure is arranged around the container receiving space.

[11] The load handling device according to any one of [8] to

[10] , wherein the container receiving space is defined within the frame structure.

[12] The load handling device according to any one of [8] to

[11] , wherein the container receiving space is bounded on four sides by the frame structure.

[13] The load handling device according to any one of [6] to

[12] , wherein one or more of the wheels are driven by a motor built into the wheel or positioned substantially adjacent to the wheel.

[14] The load handling device according to any one of [6] to

[13] , wherein one or more of the wheels comprise a wheel hub motor.

[15] The load handling device according to any one of [6] to

[14] , wherein one or more of the wheels are driven by one or more motors positioned above the container receiving space.

[16] The load handling device according to

[15] , further comprising drive transmission means arranged around the container receiving space for transmitting drive from the motor to the wheels.

[17] The load handling device according to

[16] , wherein the drive transmission means comprises a configuration of a pulley and a drive belt.

[18] The load handling device according to any one of [6] to

[17] , wherein one or more of the wheels comprise a path for cooperating with a drive belt for driving the wheels.

[19] The load handling device according to

[18] , wherein the path comprises a series of teeth for engaging with a corresponding formed part on the drive belt.

[20] The load handling device according to

[18] or

[19] , wherein the path is bounded by a pair of tires.

[21] The load handling device according to any one of [6] to

[20] , further comprising means for selectively engaging and disengaging the first set of wheels with the first set of rails, and means for selectively engaging and disengaging the second set of wheels with the second set of rails.

[22] The load handling device according to any one of [6] to

[21] , wherein one or both sets of wheels are configured to be raised and lowered relative to the other set of wheels.

[23] The load handling device according to

[22] , further comprising one or more wheel lifting devices positioned above the container receiving space and arranged to lift the wheels.

[24] The load handling device according to

[23] , wherein the wheel lifting device or each wheel lifting device is configured to lift the wheels via a link mechanism positioned at a lower part of the load handling device adjacent to the container receiving space.

[25] The load handling device according to any one of [1] to

[24] , wherein the lifting device comprises a gripping device configured to grip the container from above.

[26] The load handling device according to

[25] , further comprising a lifting mechanism configured to raise and lower the gripping device relative to the container receiving space.

[27] The load handling device according to

[26] , wherein the lifting mechanism is positioned above the container receiving space.

[28] The load handling device according to

[27] , wherein the lifting mechanism comprises a motor.

[29] The load handling device according to

[28] , further comprising a hoist arranged to be driven by the motor.

[30] The load handling device according to any one of

[25] to

[29] , wherein the gripping device is suspended from a cable that can extend and retract from the load handling device for moving the gripping device in a vertical direction.

[31] The lifting device comprises a pair of lifting arms arranged on either side of the container receiving space, the gripping device is mounted at the end of the arm, and the arm is configured to extend and retract to move the gripping device in the vertical direction. The load handling device according to any one of

[25] to

[28] .

[32] The load handling device has a center of mass positioned directly above the gripping device when the gripping device is lowered below the container receiving space. The load handling device according to any one of

[25] to

[31] .

[33] The load handling device is a self-propelled robotic vehicle. The load handling device according to any one of [1] to

[32] .

[34] Further comprising one or more batteries for supplying power to the components of the device, wherein the battery is positioned adjacent to the container receiving space and at the lower part of the device. The load handling device according to any one of [1] to

[33] .

[35] The load handling device according to

[34] , wherein the battery is positioned within the side wall of the device.

[36] A first set of parallel rails or tracks, and a second set of parallel rails or tracks extending across the first set in a substantially horizontal plane to form a grid pattern with a plurality of grid spaces. A plurality of stacks of a plurality of containers positioned below the rails and arranged so that each occupies the installation area of a single grid space. [1] to

[35] Any one of the load handling devices described above, arranged to move laterally above the stack and above the rails, the load handling device comprising a container receiving space positioned above the rails and a lifting device arranged to lift a single container from the stack into the container receiving space. A load handling device. In a storage system comprising The storage system is characterized in that the load handling device has an installation area that substantially occupies only a single grid space in the storage system.

[37] The storage system according to

[36] , wherein the storage system comprises a plurality of load handling devices according to any one of [1] to

[35] .

[38] The storage system according to

[36] or

[37] , further comprising one or more load handling devices capable of lifting a plurality of containers from the stack in a single operation.

[39] The storage system according to any one of

[36] to

[38] , further comprising one or more port locations where a plurality of containers can be removed from and / or added to the storage system.

[40] The storage system according to

[39] , wherein the load handling device is configured to transport a target container from the stack to the port location.

[41] The storage system according to any one of

[36] to

[40] , wherein the container comprises a box without a top surface.

[42] The storage system according to any one of

[36] to

[41] , wherein the containers are arranged to be connected or engaged with each other in the vertical direction when formed in a stack.

Claims

【Claim 1】 A lattice frame structure (14) for use in a warehouse environment, in which stackable boxes (10) that form a stack (12) are stacked on top of each other, the lattice frame structure (14) having a top height, comprising a plurality of upright members (16) that support horizontal members (18, 20), the horizontal members (18, 20) comprising a first set of parallel horizontal members (18) arranged perpendicular to a second set of parallel horizontal members (20), where the upright members (16) and the horizontal members (18, 20) are made of metal, where the top height of the lattice frame structure (14) includes rails (22) arranged in a lattice pattern across the top of the stack (12) for supporting a payload handling device of a robot, the rails (22) comprising a first set of parallel rails (22a) that guide the movement of the payload handling device in a first direction (X) across the top of the lattice frame structure and a second set of parallel rails (22b) arranged perpendicular to the first set (22a) that guide the movement of the payload handling device in a second direction (Y) perpendicular to the first direction across the top of the lattice frame structure (14), each rail of the first set (22a) of rails consisting of two adjacent, longitudinally extending tracks, each track being engageable with a wheel of the payload handling device, and, each rail of the second set (22b) of rails also consisting of two adjacent, longitudinally extending tracks, each track being engageable with a wheel of the payload handling device, characterized by a lattice frame structure (14).

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